//-----------------------------------------------
// sphere_sweep - radiosity bug demo scene
// by Christoph Hormann based on code from JRG
//-----------------------------------------------

#version 3.5;

global_settings {
  radiosity { recursion_limit 2 }
}

box {-1,1
  scale 12
  pigment {rgb 1}
  finish { ambient 0 }
}

/*
//   --- adding this removes the problem ---
plane {y,-14
  pigment {rgb 1}
  finish { ambient 0 }
}*/


light_source {
  <0,0,0>
  rgb 0.7
}

#declare sph_swp=true;

#if (sph_swp)
sphere_sweep {
  linear_spline
  6,
  <1,0,0>,.1
  <0,0,1>,.1
  <-1,0,0>,.1
  <0,0,-1>,.1
  <1,0,0>,.1
  <0,0,1>,.1
  //tolerance 0.0001
  pigment {rgb x+y}
  finish { ambient 0 }
  scale 2
  translate -y
}

#else

torus {1,0.1
  pigment {rgb x+y}
  finish { ambient 0 }
  scale 2
  translate -y
}

#end

camera {location <0,8,-8> look_at 0 angle 80}